Viscosity pump



Mar. 13, 1923.

J. E. NOEGGERATH VISCOSITY PUMP Filed July 8, 1920 If 11w;-

Patented Mar. 13, 1923.

JACOB EMIL NOEGGERATH, OF THE HAGUE, NETHERLANDS.

'VISCOSITY PUMP.

Application filed July 8, 1920. Serial No. 394,860.

T 0 all whom it may concern.

Be it known that I, JACOB EMIL Nonc- GERATH, a citizen of the United States, re-

siding at The Hague, Netherlands, have in;

vented certain new and useful Improvements in Viscosity Pumps, for which I filed an ap plication in Germany, August 29, 1916, and of which the following is a specification.

My invention refers to viscosity pumps.

provided with conveying grooves extending from the suction to. the pressure side, such as are found e. g. in viscosity pumps with thread grooves. Usually the grooves are separated by crests.

Experiments with such pumps have shown that their action can be considerably improved by increasing as much as possible the influence exerted upon the pumped liquid by the wall opposite the grooves. effected in different ways. If the quantity pumped per unit of groove section shall be the greatest attainable, then the groove must not exceed a certain depth in proportion to its width. Numerous experiments have shown that the output remains very small if the width of the groove is less than seven times the depth. Only when this proportion is exceeded i. e. with a groove more than seven times wider than deep it is possible to increase the quantity actually conveyed by the pump in proportion to the largest possible output considerably beyond 50 per cent till close to the theoretically attainable limit. Almost the full utilization is attained if the proportion between width and depth of the groove is larger than 10 to 1. This surprising result has been confirmed by experiments made with such pumps.

Experiments on a large scale have further shown that the best utilization is obtained, if the useful depth is between 0.1 and 1 millim. The work performed is especially great at a groove depth between and -1- This can be sure is considerably increased, while by enlarging the depth of the grooves the pumped quantity is enlarged, the pressure being in- I along its section.

The groove may have for inst. a stepped or other section. Instead of employing stepped grooves, several grooves of different depth may be combined, the crests separating the grooves of different depth belonging together need not have as narrow a slit as the main crests. It is advisable to shape a groove, whose section is determined by the required output, so that its depth is low for as wide a stretch as possible. I preferin manycases making the strip possessing a small depth wider than the deep one. I have further ascertained that the action of the pump can be improved by arranging the part of the groove possessing a small depth on the side of the groove next to the groove producing pressure of the next higher degree.

In the drawings affixed to this specification different modifications of my invention are illustrated by way of example.

Fig. 1 is a side elevation, partly in section, of a cylinder with a shallow spiral groove and a plain cylindrical casing surrounding it.

Fig. 2 is an axial section, of part of a cylinder with a stepped groove, drawn on a large scale.

Figs. 3, 4 and 5 are side elevations showing parts of cylinders provided with grooves of different forms, and

Fig. 6 is an axial section of a cylinder with a stepped groove, showing the proportions of said groove.

In the cylindrical viscosity pump shown in Fig. 1 the case a is provided on its inner face with a smooth cylindrical bore in which a well fitting equally cylindrical body 0 turns. Into this body a screw thread 0 is out, which serves as a pumping groove for the pressure liquid. The individual turns aaao've are separated from each other by crests. 0 effecting the insulation between the neighbouring grooves 0 According to the present invention, now, the width b of each groove in proportion to its depth 6 is chosen so that the groove is at least seven times as wide as it is deep. This proportion is equally valid for grooves of varying depth, the medium depth of which should be at least seven times smaller thanthe width. It appears that, the wider the groove is made in proportion to its depth, the influence of wall a of body a enveloping the groove from outside is bound to increase. And in fact the output is thus considerably increased, as has been proved by experiments,

Moreover experiments have shown that in comparison to the ordinary groove of substantially rectangular section as shown in Fig. l a, stepped groove or, better still, a groove of triangular section, such as shown for inst. on a much larger scale in Figs. 2 and3, considerably increases the effect of the pump. The influence of the stationary wall (4 upon the part of the groove possessing thesmaller depth 25 increases the pressure to such an extent that the effect of a pump fitted with a stepped groove such as shown in Fig.2 is. increased considerably, provided the passage section be of the sa-me size as that, of the normal groove shown in Fig. 1. Preferably in each under-section of the stepped or other groove the width of the groove (6 and 6 is to be chosen more than seven times larger than the depth of the groove (6 and 25 The triangular section of the groove may for inst. correspond to the one shown in Fig. 4, in which the bottom of the groove has, a narrow cylindrical portion, on to which the lateral bordering wall of the groove is joined, if desired, by a curve. The walls of the groove may as well possess a curved section such as illustratedv e. g. in Fig. 5. It is advisable in certain cases that the part of the section having a small depth should be next to the groove being under higher pressure. Thus for inst. in Fig. 6 the liquid is assumed as being pumped from right to left, i. e. that the pressure increases between groove 0 and groove 0' and further 0 Obviously in each groove the part b producing the higher pressure is arranged on the side of the groove section next to the groove being under higher pressure.

To obtain from the pump a large output and at the same time high pressure it is advisable not to provide the groove with a uniform depth allover its width (Fig. 1), but a varying depth.

The invention is not restricted to the constructions previously described in detail and shown by the figures, but it encompasses as well every kind ofmodification of same.

I claim:

1. In a rotary pump in combination, a stationary body, a rotary body adjacent to said stationary body and an open groove in that surface of one of said bodies which faces the other body, the proportion of breadth to the average depth of said groove being at least 7 to 1.

2. In a rotary pump in combination, a

stationary cylindrical sleeve, a cylindrical body rotatably disposed within said sleeve and'an open groove in the circumference of one of said bodies, the proportion of breadth to the average depth of said groove being at least 7 to 1.

3. In a rotary pump incombination, a stationary cylindrical sleeve, a cylindrical body rotatably disposed within said sleeve and a grooveof variable depth in the circumference of one of said bodies, the proportion of breadth to the average depth of said groove being at least 'Zto 1.

4. In a rotary pump in combination, a stationary cylindrical sleeve, a cylindrical body rotatably disposed within said sleeve and a stepped groove in the circumference of one of said bodies, the proportion of breadth to the average depth of said groove being at least 7 to 1.

5. In a rotary pump in combination, a stationary. cylindrical sleeve, a cylindrical body rotatably disposed within said sleeve, a stepped groove in the circumference of one of said bodies and webs between the stepsof said groove, the proportion of, breadth to the averagedepthof said groove being at least 7 to 1.

Intestimony whereof I aiiix my signature.

JACOB EMIL .NOEGGERATH. 

